Automatic parking systems can maneuver a vehicle from a traffic lane into a parking spot, e.g., to perform parallel, perpendicular or angle parking. An automatic parking system aims to enhance driver comfort and safety in constrained environments where much attention and experience is required to steer the vehicle. The parking maneuver is typically achieved by coordinated control of the steering angle and speed, taking into account the vehicle's environment to achieve collision-free motion within the available space. For example, when parallel parking, a vehicle's automatic parking system can use ultrasonic sensors and cameras to locate a suitable parking space. The automatic parking system might operate the steering wheel of a vehicle, while a driver controls the acceleration, braking and shifting.
When departing a parallel parking space and merging into to traffic, a vehicle requires clearance, i.e., enough space to clear any obstacles or vehicles in front of the exiting vehicle and to safely merge into traffic in a single forward move. Unfortunately, present mechanisms for determining clearance for exiting a parking space are lacking.